1. Field of the Invention
The present invention relates to an assembly and method for interconnecting an electronic package to a circuit board.
2. Description of Related Art
Semiconductor devices are typically housed within a plastic or ceramic package. Electronic packages are typically rectangular in shape and include a plurality of conductive pads on the bottom surface of the package. The pads are sometimes arranged in a grid like pattern to increase the output density of the package.
Electronic packages are typically mounted to a printed circuit board which has a plurality of surface pads or plated through holes arranged in the same pattern as the conductive pads on the packages. The electronic packages are typically coupled to the printed circuit board by soldering the conductive pads of the package to the surface pads of the board. The distance between the bottom of the package and the top of the board is very narrow, making it difficult to inspect all of the solder joints of the assembly. Solder joints are also susceptible to fatigue created by a continuous thermal cycling of the package and board. Repairing soldered electronic packages typically requires reflowing the solder of the entire board, which degrades the board and other components of the assembly.
Some board assemblies include a hold down clamp which mechanically couples the package(s) to the board. The clamp is typically connected to a spring which applies a pressure to the package and board. Instead of solder, such assemblies use pogo pins, conductive elastomers other spring-like members to interconnect the conductive pads of the package to the pads of the circuit board. The pins or elastomers are typically captured by an interposer which is placed between the package and board. The electronic package is typically assembled to the board by first placing the interposer and spring-like members on top of the circuit board, placing the package on top of the spring-like members and then mounting the clamp onto the package.
The clamp is typically attached to the circuit board by a number of screws. Assembling and repairing such a clamp assembly requires the constant insertion and removal of the screws. The screws are typically quite small, thereby requiring a non-conventional screw driver. It is desirable to have a package/board assembly which does not require solder and allows the package to be detached from the board without removing screws or other fasteners.